Barium titanium oxide-containing fluidizable cracking catalyst composition

ABSTRACT

A cracking catalyst composition comprising a zeolitic, crystalline aluminosilicate, a matrix material and a barium titanium oxide. The catalyst composition is particularly suitable for cracking metal-containing hydrocarbon feedstocks.

BACKGROUND OF THE INVENTION

The present invention relates to a fluidizable cracking catalystcomposition comprising a zeolitic, crystalline aluminosilicate, a matrixmaterial and a barium compound. A catalyst composition of this type issuitable for cracking oil feedstocks and is disclosed in U.S. Pat. No.4,473,463. According to the description in that patent, barium compoundsare incorporated into or applied onto cracking catalysts to preventdeleterious effects caused by metal contamination in oil feedstocks. Thecatalysts generally contain a silica-alumina matrix in which zeoliticmaterials are embedded. Preferably, use is made of barium acetylacetonate. In this U.S. patent, the results obtained are described in anexample in which a cracking catalyst contaminated with metals isre-activated in a treatment with barium acetyl acetonate. This compound,however, and many other barium compounds are not quite suitable to beused for composing a metal resistant cracking catalyst, as appears frommetal resistance and micro-activity tests (referred to as MR test andMAT test, respectively).

A barium compound in which the cracking catalyst composition .Iadd.is.Iaddend.of the above well-known type but which contains a bariumtitanium oxide has now been found which does not show the abovedrawback.

Use of barium compounds in cracking catalysts is also known from otherpatent specifications. U.S. Pat. No. 4,179,409 describes a crackingcatalyst which in addition to a zeolite and an inorganic oxide gelmatrix contains a perovskite. As a result, the cracked oil will have ahigher octane number. The perovskite may be a barium compound, such asbarium zirconate (BaZrO₃).

In the cracking process of EP No. 0 063 712, use is made of metal traps,such as type A zeolite, which may contain for instance a bariumcompound. It should be added that U.S. Pat. No. 4,451,355 relates to acracking catalyst which in addition to a zeolitic aluminosilicate and amatrix material contains a calcium-containing additive for trappingmetal contaminations. Particular calcium/titanium-containing compounds,including calcium titanate (CaTiO₃), are considered to be particularlysuitable for this purpose.

SUMMARY OF THE INVENTION

The present invention provides a cracking catalyst compositioncomprising a zeolitic, crystalline aluminosilicate, a matrix materialand a barium titanium oxide. The catalyst composition is particularlysuitable for cracking metal-containing hydrocarbon feedstocks.

DETAILED DESCRIPTION OF THE INVENTION

The barium titanium oxides that may be included in the present catalystcomposition are described by, inter alia. D. E. Rase and R. Roy in J.Amer. Ceram. Soc. 38, 108 (1955), G. H. Jonker and W. Kwestroo in J.Amer. Ceram. Soc. 41, 390 (1958) and H. M. O'Bryan and I. Thomson in J.Amer. Ceram. Soc. 57, 522 (1974). Examples of suitable barium titaniumoxides include Ba₂ TiO₄, BaTiO₃, Ba₂ Ti₅ O₁₂, Ba₆ Ti₁₇ O₄₀, BaTi₃ O₇,Ba₄ Ti₁₃ O₃₀, BaTi4O₉ and Ba₂ Ti₉ O₂₀. Particularly suitable are Ba₂TiO₄, BaTi₃ O₇ and especially BaTiO₃ (barium titanate).

As the zeolite crystalline aluminosilicate may be used all molecularsieves commonly employed for cracking catalysts. It is preferred thatuse should be made of synthetic crystalline aluminosilicates having apore diameter in the range of 3 to 15 angstroms. Examples thereofinclude the zeolites A, X, Y, ultrastabilized sieves, ZK-4, ZK-5, ZSM-5,ZSM-11 and ZSM-12. It is preferred that zeolites of the types X, Yand/or ultrastabilized sieves should be applied. To ensure propercatalyst activity the cations of these zeolites, which are oftenprepared in the sodium form, need to be exchanged. For this ionexchange, use is generally made of solutions containing rare earth metalions and/or ammonium or hydrogen ions. The exchange is as a rule carriedon to such a level that the zeolites and the ready catalyst contain lessthan 4% by weight, preferably less than 0.5% by weight, of sodium.

As matrix material can be used all well-known matrix materials suitablefor embedding zeolitic, crystalline aluminosilicates, such as silica,alumina, magnesia, zirconia, titania, boris, aluminum chlorohydrol andmixtures thereof. Preference is given to silica, silica-alumina andalumina.

In addition to the barium titanium oxide and the alumino silicate, othercomponents may also be incorporated into the matrix material. Asexamples thereof may be mentioned clays such as kaolin, bentonite andlayered clays as discussed in U.S. Pat. Nos. 3,252,757, 3,252,889 and3,743,594, montmorrilonite, etc.

To augment the octane number of the petrol fraction produced, aluminaparticles as described in U.S. Pat. No. 4,182,693 may be incorporatedinto the catalyst composition.

Moreover, use may be made of usual amounts of one or more passivatorswhich may contain antimony, tin and the like. They particularly serve toprevent excessive formation of hydrogen during the cracking process.

To reduce SO_(x) emission and to promote the conversion of CO to CO₂, anoxidation promoting metal or metal compound may be incorporated into thepresent composition. The cracking catalyst composition generallycontains 0.05-1000 ppm of an oxidation promoting metal or metalcompound. Suitable for that purpose are noble metals or compoundsthereof of group VIII of the periodic system, such as Pt, Pd, Ir, Rh, Osand Ru. Also suitable to that end are rare earth metals or compoundsthereof. Examples of suitable oxidation promoters also include Cr andCu, and compounds thereof. It is preferred that use should be made of0.1 to 100 ppm, more particularly 0.1-50 ppm of a noble metal of groupVIII. Most preference is given to the incorporation into the catalyst of0.1-10 ppm of platinum or palladium. These metals may be incorporated inthe catalyst in a known manner, for instance by impregnation with acorresponding salt solution.

The components of the catalyst composition may be combined with thematrix material in a manner known in itself. Suitable methods ofpreparation are described, among other places, in U.S. Pat. Nos.3,609,103 and 3,676,330. For instance, the barium titanium oxide and thealuminosilicate may be combined with the matrix material when the lattermaterial is already in the gelled state. After proper mixing andsubsequent spray drying the ready catalyst composition is obtained.Alternatively, the various components may be added to a matrix materialin the form of a sol. This sol bonding agent can be formed into a gelbefore or during spray drying. The latter procedure is to be preferredin that it permits obtaining catalyst compositions having a relativelyhigh density. Thus, apparent densities higher than 0.5 g/ml, preferablyhigher than 0.70 g/ml are simple to realize.

A suitable catalyst composition according to the present inventioncomprises 5-50, preferably 10-30 percent by weight of a zeolitic,crystalline aluminosilicate and 0.01-30, preferably 1-20, moreparticularly 1-10 percent by weight of barium titanium oxide, which twocomponents are embedded in 10-90 percent by weight of matrix material.It is preferred that the aluminosilicate should consist of a type Yzeolite or an ultrastabilized zeolite exchanged for rare earth metalions and/or ammonium or hydrogen ions. The matrix material is preferablya silica, silica-alumina or alumina formed into a gel by spray dryingthe total composition. Particularly in uses requiring a reduction ofSO_(x) emission, it is preferred that there should be incorporated0.1-10 ppm of platinum into the catalyst composition.

The cracking catalyst composition may optionally consist of a physicalmixture of:

a. catalytically active particles comprising a zeolitic crystallinealuminosilicate embedded in matrix material; and

b. catalytically less active particles comprising barium titanium oxideembedded in matrix material. This embodiment of the invention has theadvantage that the amount of barium titanium oxide added can readily beadapted to the feedstock to be cracked.

Very suitable is a physical mixture in which:

a. the catalytically active particles contain 10-80, preferably 20-40percent by weight of zeolitic, crystalline aluminosilicate, 5-60,preferably 20-50 percent by weight of clay and 5-85, preferably 10-30percent by weight of silica, silica-alumina or alumina, and

b. the catalytically less active particles contain 10-80, preferably10-40 percent by weight of barium titanium oxide, and 10-90, preferably10-30 percent by weight of silica, silica-alumina, or alumina and,optionally, 10-50 percent by weight of clay.

Also in this mixture the silica, silica-alumina or alumina in thecatalytically active and/or less active particles perferably consists ofsilica, silica-alumina or alumina formed into a gel by spray drying therespective particles. Especially if augmentation of the octane number ofpetrol fractions is envisaged, then aluminum oxide particles may beincorporated into the catalytically active and/or less active particlesin an amount of up to in all 40, preferably 1-15 percent by weight ofaluminum oxide particles.

It is also possible for the two different types of particles to havedifferent diameters. For instance, the catalytically active paticles mayhave a diameter of 80-125 microns and the catalytically less activeparticles a diameter of 30-75 microns.

Moreover, into one or more of the two components of the mixture a noblemetal of group VIII of the periodic system may be incorporated in aconcentration of 0.1-100 ppm, preferably 0.1 to 50 ppm, calculated onthe weight of the total mixture. It is again preferred then thatplatinum should be used in an amount of 0.1-10 ppm.

The present catalyst composition is suitable for use in a conventionalprocess for cracking feeds. Catalytic cracking is normally carried outat a temperature of 375°-650° C., more particularly 460°-560° C. Thepressure applied is generally in the range from atmospheric pressure toa pressure of 7 atmospheres, more particularly a pressure from 1 to 3atmospheres. Regeneration with steam is generally carried out at540°-825°, more particularly 750°-800° C. Suitable feeds include thehydrocarbon materials that are normally subjected to cracking.

The catalyst composition is particularly suitable for crackingmetal-containing hydrocarbon feedstocks having a boiling range whichgenerally ends at a temperature higher than 480° C., a density greaterthan 900 kg/cm³, metal concentration (Ni and V) of more than 1 ppm and aConradson carbon content higher than 1%. The present catalystcomposition, however, is preferably applied to heavier feeds, such asresidues that include a substantial concentration of metals and/orasphaltenes.

If the feedstock has a high metal content, preference is given to aprocess in which the feedstock to be cracked is first brought intocontact with the barium titanium oxide-containing particles andsubsequently with the zeolite-containing particles. The feedstock willbe demetallized then before cracking.

EXAMPLE 1

The catalyst compositions in Table 1 were obtained by mixing the variouscatalyst constituents with a silica-alumina sol. The total compositionswere milled in a colloid mill, gelled by spray drying, and the resultingparticles were exchanged with (NH₄)₂ SO₄, and dried. The performance ofthe resulting catalyst compositions was measured by carrying out MAT andMR tests. The MAT test corresponds to test method D3907-80 of theAmerican Society for Testing and Materials (ASTM). The MR test isdescribed on pp. 80-84 of the Ketjen Symposium book, 1982, Amsterdam,The Netherlands.

The MAT and MR tests are used for determining the activity of thecracking catalyst prior to (MAT test) and after (MR test) contaminationof the catalyst with metals (nickel and vanadium). The higher the rateconstant k and the conversion, the more active the catalyst will be. Theresults mentioned in Table 2 illustrate the extraordinary effectivenessof catalysts containing a barium titanium oxide, in particular bariumtitanate.

The results also show that the amount of barium titanium oxide in thetotal catalyst composition can be varied within wide limits. Forcomparison, the table gives the test results obtained with additivesthat are known from the state of the art discussed hereinbefore.

                                      TABLE 1                                     __________________________________________________________________________    Catalyst Composition and Properties                                                      BaTiO.sub.3         BaTi.sub.3 O.sub.7                                                                 BaAcAc*                                                                            BaCO.sub.3                                                                         BaZrO.sub.3                                                                        GaTiO.sub.3                           2.5% 5%   10%  20%  8.5% 10%  20%  20%  20%                        __________________________________________________________________________    REHN.sub.4 Y-zeolite                                                                     15   15   15   15   15   15   15   15   15                         (%; SiO.sub.2 /Al.sub.2 O.sub.3 = 5)                                          Silica-alumina                                                                           20   20   20   20   20   20   20   20   20                         97%/3%                                                                        Kaolin (%) 62.5 60   55   45   56.5 55   45   45   45                         Na.sub.2 O (%)                                                                           0.23 0.28 0.28 0.26 0.26 0.24 0.25 0.23 0.24                       RE.sub.2 O.sub.3 (%)                                                                     1.7  2.0  1.9  2.0  1.8  2.0  2.0  1.7  2.0                        SA (m.sup.2 /g; fresh)                                                                   113  136  116  99   124  144  106  114  89                         SA (m.sup.2 /g; 795° C.)                                                          54   58   52   45   48   39   30   --   28                         ABD (g/cal)                                                                              0.70 0.72 0.76 0.80 --   0.56 0.80 --   0.78                       __________________________________________________________________________     % = weight percentage                                                         *Barium acetyl acetonate                                                 

                                      TABLE 2                                     __________________________________________________________________________    Test Results                                                                            BaTiO.sub.3         BaTi.sub.3 O.sub.7                                                                 BaAcAc                                                                             BaCO.sub.3                                                                         BaZrO.sub.3                                                                        CaTiO.sub.3                           2.5% 5%   10%  20%  8.5% 10%  20%  20%  20%                         __________________________________________________________________________    MAT - 795° C.-Test:                                                    k         16.9 17.2 16.1 15.0 15.2 13.2 10.2 11.6 9.4                         Conversion %                                                                            58.5 58.7 57.0 55.3 55.7 52.2 46.0 49.2 44.0                        Gas total %                                                                             11.2 10.9 10.5 10.3 10.9 9.2  8.4  8.5  7.5                         Gasoline %                                                                              44.8 45.2 44.2 42.6 42.6 41.0 35.7 39.0 35.1                        LCO %     23.6 23.6 23.3 23.8 23.7 23.3 24.4 23.3 23.4                        Coke %    2.5  2.6  2.4  2.3  2.3  2.0  1.9  1.7  1.4                         MR-Test:                                                                      V (ppm)   3158 3201 3324 2971 3120 3238 3076 3270 3257                        Ni (ppm)  952  1026 995  998  1085 1007 1016 954  860                         k         19.8 24.2 22.2 21.5 18.4 9.6  20.4 17.1 14.9                        Conversion %                                                                            62.1 66.7 64.7 64.2 60.4 44.1 62.8 58.8 55.1                        Gas total %                                                                             12.6 13.6 13.6 13.7 12.4 7.0  11.9 12.7 10.4                        Gasoline %                                                                              45.4 48.1 46.1 46.1 44.6 34.2 46.7 42.6 41.6                        LCO %     22.5 20.6 21.3 21.6 22.2 25.1 21.0 21.7 23.2                        Coke %    4.1  5.0  5.0  4.4  3.6  3.0  4.3  3.6  3.2                         H.sub.2   0.13 0.12 0.13 0.12 0.15 0.24 0.14 0.09 0.16                        __________________________________________________________________________

EXAMPLE 2

Using the procedure described in Example 1, catalysts A and B wereprepared that contain an ultrastable Y-zeolite and are furthercharacterized by the composition and properties mentioned in the tablebelow.

                  TABLE III                                                       ______________________________________                                        Catalyst Composition and Properties                                                          Catalyst A                                                                            Catalyst B                                             ______________________________________                                        Ultrastable Y-zeolite                                                                          25        25                                                 (a.sub.0 = 24.53 Angstroms)                                                   Kaolin (%)       55        35                                                 Silica (%)       20        20                                                 BaTiO.sub.3 (%)  0         20                                                 RE.sub.2 O.sub.3 (%)                                                                           0         0                                                  Na.sub.2 O (%)   0.16      0.28                                               SA (m.sup.2 /g; fresh)                                                                         232       259                                                SA (m.sup.2 /g; 795° C.)                                                                132       129                                                ______________________________________                                    

The test results in the following Table IV show the excellent resistanceto metal (see MR test) of catalyst B, which contains barium titanate.

                  TABLE IV                                                        ______________________________________                                        Test Results                                                                                Catalyst A                                                                            Catalyst B                                              ______________________________________                                        MAT - 795° C.-Test:                                                    k               12.8      13.3                                                Conversion      51.7      52.2                                                Gas total (%)   11.7      11.3                                                Gasoline (%)    38.4      39.6                                                LCO (%)         24.9      24.8                                                Coke (%)        1.6       1.7                                                 MR-Test:                                                                      V (ppm)         3350      3132                                                Ni (ppm)        1225      1045                                                k               3.7       15.8                                                Conversion (%)  32.3      56.9                                                Gas total (%)   5.8       13.2                                                Gasoline (%)    23.7      40.8                                                LCO (%)         26.6      24.2                                                Coke (%)        2.9       2.9                                                 H.sub.2 (%)     0.65      0.36                                                ______________________________________                                    

EXAMPLE 3

Using the procedure described in Example 1, the followingY-zeolite-containing "active" and barium titanate-containing "lessactive" catalyst particles were prepared.

                  TABLE V                                                         ______________________________________                                        Catalyst Composition                                                                         Active Less Active                                                            Particles                                                                            Particles                                               ______________________________________                                        RENH.sub.4 -Y-zeolite (%)                                                                      30        0                                                  Kaolin (%)       50       70                                                  Silica (%)       20       20                                                  BaTiO.sub.2 (%)   0       10                                                  ______________________________________                                    

Then a mixture was prepared of equal amounts by weight of the two typesof particles. The mixture contained 1.6 RE₂ O₃, 0.25% Na₂ O and had anSA=109 m² /g. The MAT and MR test results show the effectiveness of thiscracking catalyst mixture.

                  TABLE VI                                                        ______________________________________                                        Test Results                                                                  ______________________________________                                        MAT - 795° C.-Test                                                     k                 16.6                                                        Conversion (%)    57.9                                                        Gas total (%)     10.9                                                        Gasoline (%)      44.4                                                        LCO (%)           23.1                                                        Coke (%)          2.6                                                         MR-Test                                                                       V (ppm)           3230                                                        Ni (ppm)          935                                                         k                 16.7                                                        Conversion (%)    58.2                                                        Gas total (%)     11.8                                                        Gasoline (%)      42.5                                                        LCO (%)           22.8                                                        Coke (%)          3.8                                                         H.sub.2 '(%)      0.19                                                        ______________________________________                                    

What is claimed is:
 1. A fluidized cracking catalyst comprising a zeolitic, crystalline aluminosilicate, a matrix material and a barium titanium oxide.
 2. A catalyst according to claim 1, wherein said barium titanium oxide and said zeolitic, crystalline aluminosilicate are collectively incorporated in a matrix comprising said matrix material.
 3. A catalyst according to claim 1, comprising 1 to 20 percent by weight of said barium titanium oxide.
 4. A catalyst according to claim 1, comprising 1 to 10 percent by weight of said barium titanium oxide.
 5. A catalyst according to claim 4, comprising 10 to 30 percent by weight of said zeolitic, crystalline aluminosilicate.
 6. A catalyst according to claim 5, wherein said barium titanium oxide and said zeolitic, crystalline aluminosilicate are embedded in 10 to 90 percent by weight of said matrix material.
 7. A catalyst according to claim 1, wherein said barium titanium oxide is physically separated from said zeolitic, crystalline aluminosilicate, said catalyst comprising:a. catalytically active particles comprising said zeolitic, crystalline embedded in said matrix material, and b. catalytically less active particles comprising said barium titanium oxide embedded in said matrix material.
 8. A catalyst according to claim 7, wherein said catalytically less active particles contain 10 to 40 percent by weight of barium titanium oxide.
 9. A catalyst according to claim 8, wherein said catalytically active particles contain 20 to 40 percent by weight of said zeolitic, crystalline aluminosilicate.
 10. A catalyst according to claim 1, wherein said barium titanium oxide is barium titanate.
 11. A catalyst according to claim 1, further comprising a clay.
 12. A catalyst according to claim 1, further comprising a passivator.
 13. A catalyst according to claim 1, further comprising an oxidation promoting metal or metal compound.
 14. Particles comprising barium titanium oxide embedded in a matrix material.
 15. Particles according to claim 14, wherein said barium titanium oxide is barium titanate. .Iadd.
 16. A catalyst according to claim 7, wherein said barium titanium oxide is barium titanate..Iaddend..Iadd.17. A catalyst according to claim 1, wherein said aluminosilicate is selected from the group consisting of zeolites A,X,Y, ultrastabilized sieves, ZK-4, ZK-5, ZSM-5, ZSM-11 and ZSM-12..Iaddend..Iadd.18. A catalyst according to claim 1, wherein said matrix material is selected from the group consisting of silica, silica-alumina, alumina, zirconia, titania, magnesia and mixtures thereof..Iaddend..Iadd.19. A catalyst according to claim 1, wherein the barium titanium oxide is selected from the group consisting of BaTiO₃, BaTi₃ O₇, BaTi₄ O₉, Ba₂ TiO₄, Ba₂ Ti₅ O₁₂, Ba₂ Ti₉ O₂₀, Ba₄ Ti₁₃ O₃₀ and Ba₆ Ti₁₇ O₄₀..Iaddend. 